/Engine/Plugins/Runtime/PacketHandlers/AESGCMHandlerComponent/Source/Public/AESGCMHandlerComponent.h
Replace the key used for encryption with NewKey if NewKey is exactly KeySizeInBytes long.
virtual void SetEncryptionData ( const [FEncryptionData](API\Runtime\CoreUObject\UObject\FEncryptionData) & EncryptionData )